No pressure to one port of fuel pulse pump

[Lhaney1]

Initially Posted in wrong forum. Moving here... sn is ot 701189

Engine is a 2003 Opti 225. Been chasing fuel starvation problems for over a month. I have discovered that the pulse pump pressure port coming from the #2 cylinder crank case puts out hardly any noticeable air pulse, while the other( -#6) is strong every stroke. Cylinder Compression are good. Is this definitely a failed reed valve. I tried inspection with a mirror through throttle body and didn’t see any broken reeds, but I don’t know what else could cause a lack of pressure in part of the crankcase other than failed reeds. Any other causes of lost crank case pressure or things to check? Should I pull the air inlet for closer inspection? Thanks for reading. I’ve learned a lot from reading through posts on this site. Unfortunately I can’t find anything about no pulses coming from crankcase fitting.

Explain why you believe you have a starvation problem. Does it die at idle, Do you have to pump the bulb to keep it running or loss of power at high RPM
Do you have a oil leak coming from under the flywheel?
I would use a dual vacuum/pressure gauge to test and compare to the good cylinder, also check line and fitting for obstructions
I would think you would have a poor idle and poor throttle response if it were a reed

Yes it dies at idle and when I check the vst and it’s practically empty. Yes it will stay running if I pump the ball. I haven’t ran to high rpm since this happens. The difference in air pulses is extremely noticeable and I can’t find what the pressure /vacuum should be anyway. Idle seemed fine 580+\- 20 rpm. Throttle response doesn’t have a hiccup on the hose. Now that you said it I did notice some sludgey oil spots on top of the air intake housing last night. What does this mean?

sounds like a upper crankshaft seal. If it’s bad will #2 cylinder crankcase not pressurize? ...and therefor not operate pulse pump?..

[Savage]

Check the reeds by removing the intake plenum.

[Lhaney1]

Check the reeds by removing the intake plenum.

1 reed gone. Problem solved...or maybe just has started.

[Savage]

Better find out where it is now.

[Lhaney1]

How? I do have access to a quality borescope. I assumed the petal was in 1000 pieces? Is this typically not the case? I would love to find it but what am I looking for? Scan the intake and crank case with the scope and cylinder heads via plugs? Am I looking for damage or have others actually found and remove pieces?

[EuropeanAM]

If you are LUCKY, the piece passed through the engine. They commonly either end up on top of the piston, or become lodged somewhere in the intake runner area, only to later "surprise" the piston.

Strongly recommend TDR Reed as the replacement- Rhonda (in our Parts Department) keeps those in stock.

[Lhaney1]

Thanks. I have several hours...15ish since the reed broke. The lift pump would still have enough suction to siphon gas from an aux tank. Due to this I thought it was boat side for a month. Fished using aux tank. Changed hoses and everything and tried it. Stalled. Got the aux tank back out and put in new location(lower on deck) and no more worky. Realizes engine side. Couple more weeks of head scratching and I found the reed was missing. I am hoping the reed is at the bottom of the bay. I borescoped the crank case and in through all the plugs last night. Didn’t see anything. No cyclinder scratches, metal flakes, entire reeds...nothing. I plan to take another hard look before reassembling. I’ll look at the piston tops and intakes very closely. Thank again for the reply.
-logan